Relict granulites in the Ross orogen of northern Victoria Land (Antarctica): II - geochemistry and paleo-tectonic implications

Relict granulite facies rocks of the region between Priestley and Aviator Glaciers (Wilson Terrane, Ross Orogen) comprise an older supracrustal sequence which has been intruded by meta-igneous mafic and intermediate granulites and by later synmetamorphic intrusive enderbite and charno-enderbite. The intrusive granulites show chemical patterns which are similar to the ∼ 1000-Ma-old Mawson Charnockite of Mac Robertson Land. Despite significant chemical modifications which have affected most granulite rocks during the Ross amphibolite facies metamorphic overprinting, Cpx ± Opx-bearing felsic granulites of the Campbell Glacier still retain similarities to depleted compositions. Whole-rock SmNd model ages ranging between 1.8 and 2.2 Ga and comparison of the meta-igneous granulites with similar rocks of the Proterozoic mobile belts of East Antarctica support the idea that the relict granulite rocks of the Wilson Terrane represent reworked Proterozoic fragments of the East Antarctic Craton in the Early Palaeozoic Ross Orogen. © 1995.